DTC U0554: Invalid Data Received from Accessory Protocol Interface Module: Description

WARNING: This page is about a different car, the 2018 Lincoln Navigator. However, it is still accessible from the selected car via links, so may be relevant.

The PSCM monitors the HS-CAN messages when the ignition has been on for more than 5 seconds, the voltage to the PSCM is greater than 6.5 volts and there are no DTCs present inhibiting PSCM operation.

DTC U0554:00 (Invalid Data Received from Accessory Protocol Interface Module: No Sub Type Information) - This DTC sets if the PSCM does not receive a value of "fresh data" in the trailer back up assist message from the APIM.